The Big Bang
to find the answer. There are two types of models: Big Bang and Steady State.
The Big Bang model postulates that about 15 to 20 billion years ago, the
the Big Bang, all of the matter and radiation of our present universe were
packed together in the primeval fireball–an extremely hot dense state from
space. The matter and radiation of that early stage rapidly expanded and cooled.
It maintains the same average density of matter forever.
There are observational evidences found that can prove the Big Bang model
is more reasonable than the Steady State model. First, the redshifts of distant
away, the spectral line of that galaxy observed will have a shift to the red end.
The faster the galaxy moves, the more shift it has. If the galaxy is moving
closer, the spectral line will show a blue shift. If the galaxy is not moving,
there is no shift at all. However, as astronomers observed, the more distance a
galaxy is located from Earth, the more redshift it shows on the spectrum. This
means the further a galaxy is, the faster it moves. Therefore, the universe is
expanding, and the Big Bang model seems more reasonable than the Steady State
The second observational evidence is the radiation produced by the Big Bang.
The Big Bang model predicts that the universe should still be filled with a
primeval fireball in the past. The primeval fireball would have sent strong
shortwave radiation in all directions into space. In time, that radiation would
strike Earth as microwave radiation. In 1965 physicists Arno Penzias and Robert
Wilson detected microwave radiation coming equally from all directions in the
sky, day and night, all year.3 And so it appears that astronomers have detected
the fireball radiation that was produced by the Big Bang. This casts serious
doubt on the Steady State model. The Steady State could not explain the
Since the Big Bang model is the better model, the existence and the future
of the universe can also be explained. Around 15 to 20 billion years ago, time
began. The points that were to become the universe exploded in the primeval
fireball called the Big Bang. The exact nature of this explosion may never be
known. However, recent theoretical breakthroughs, based on the principles of
quantum theory, have suggested that space, and the matter within it, masks an
called quantum weirdness.4
Before the universe began, this chaos was all there was. At some time, a
portion of this randomness happened to form a bubble, with a temperature in
expanded. For an extremely brief and short period, billionths of billionths of
have a diameter of a few centimetres. The temperature had cooled enough for
matter than antimatter was formed.5 The fireball, and the smoke of its burning,
was the universe at an age of trillionth of a second.
The temperature of the expanding fireball dropped rapidly, cooling to a few
billion degrees in few minutes. Matter continued to condense out of energy,
first protons and neutrons, then electrons, and finally neutrinos. After about
an hour, the temperature had dropped below a billion degrees, and protons and
this cloud of energy, atoms, and neutrinos had cooled enough for galaxies to
form. The expanding cloud cooled still further until today, its temperature is
a couple of degrees above absolute zero.
the initial Big Bang, the universe attained a speed of expansion. If that speed
stop its expansion. Such a universe is said to be open. If the velocity of
expansion is slower than the escape velocity, the universe will eventually reach
the limit of its outward thrust, just like a ball thrown in the air comes to the
may be the Big Bang to the beginning of another universe, as the fireball formed
universe is said to be closed, and pulsating.
If the universe has achieved escape velocity, it will continue to expand
forever. The stars will redden and die, the universe will be like a limitless
emptier, as the fundamental particles of matter age, and decay through time. As
such as positrons and electrons will be orbiting each other at distances of
hundreds of astronomical units.7 These particles will spiral slowly toward each
all, the Big Bang model is only an assumption. No one knows for sure that
exactly how the universe began and how it will end. However, the Big Bang model
is the most logical and reasonable theory to explain the universe in modern
2. Ibid., p. 130.
4. Terry Holt, The Universe Next Door, New York: Charles Scribner’s Sons,
1985. p. 326.
5. Ibid., p. 327.
USA: Tab Books Inc., 1986. p. 72.
7. John Gribbin, In Search Of The Big Bang, New York: Bantam Books, 1986.
Boslough, John. Stephen Hawking’s Universe. New York: Cambridge
Caes, J. Charles. Cosmology, The Search For The Order Of The
Universe. USA: Tab Books Inc., 1986.
Gribbin, John. In Search Of The Big Bang. New York: Bantam
Holt, Terry. The Universe Next Door. New York: Charles
Scribner’s Sons, 1985.
Kaufmann, J. William III. Astronomy: The Structure Of The
Universe. New York: Macmillan Publishing Co., Inc., 1977.
Mache, L. Dinah. Astronomy. New York: John Wiley & Sons, Inc.,
Silk, Joseph. The Big Bang. New York: W.H. Freeman and Company,